Operating mechanism



July 1, 1941. c. THUM]M EI'AL OPERATING MECHANISM Filed Oct. 1Q i938 2 Sheets-Sheet 1 ask rville,

ln'vencorsz' Carl Thum i m 32h J. B Their- Attorney.

iUH I July 1, c THUM|M ETAL OPERATING MECHANISM Filed Oct. 1, 1.938 ZSheets-Sheet 2 Inventors: Carl Thumim, Ralph J. Baskerville,

y Th eh" Attorney.

Patented July 1, 1941 OPERATING MECHANISIVI Carl Thumim and Ralph J.'Baskervil1e, Yeadon, Pa., assignors to General Electric Company, a corporation of New York Application October 1, 1938, Serial No. 232,835

3 Claims.

Our invention relates to operating mechanisms, such as, for example, those used for closing and latching closed against an opening biasingforce electric circuit breakers, and more particularly to sensitive tripping means for unlatching and causing opening of the circuit breaker under influence of said biasing means.

In the case of operating mechanisms for oil circuit breakers, the tripping devices therefor generally fall within two types, one type being adapted for using tripping energy equivalent approximately to 500, watts, as in the case where external power can be applied by .a potential trip coil, and the other type for energy of the order of but volt amperes as Where power is obtained from the main line through a transformer. In the latter case the tripping mechanism must be much more sensitive to small releasing forces than the first type, and usually the tripping force required is reduced by the use of additional linkages, toggles, etc., as compared with a much more simple mechanism of the potential trip type.

In accordance with the present invention there is providedan independent tripping unit that is particularly adapted .for utilizing the small tripping forces available for mechanisms of the second type referred to, and which can be universally and readily applied to standard operating mechanisms of various sizes and types without altering the essential structure thereof. For example, when but a comparatively small tripping force is available for a mechanism of the potential type, the tripping unit embodying the present invention can be incorporated in the aforesaid mechanism without alteration of the design,.and by simple attachment thereto. When the sensitive tripping coil of the unit is energized in response to a tripping impulse, spring energy is instantly released to deliver a predetermined blow to the potential trip latch of the standard mechanism.

The principal object of our invention, therefore, is the provision of an improved trip-ping arrangement including a unit having general application to operating mechanisms of different types for insuring positive high speed tripping regardless of the magnitude of the tripping force.

Our invention will be more fully set forth in the fol-lowingdescription referring to the accompanying drawings, and the features of novelty whichcharacterize our invention will be pointed out with particularity in the claims annexed to and .forming a part of this specification.

Referring to the drawings, Fig. l is an elevational view of a standard solenoid type operating mechanism embodying thepresent invention, and

Fig. 2 is a fragmentary view of anotheriorm .of standard solenoid operating mechanism to which the. present. invention. is equally applicable.

The operating mechanismshown by.Fig.,1c.omprisesa solenoid I for. actuating a reciprocally guided rod Zthat is connected, for. example, to a circuit breaker. Themechanism per. seforms no part of the present invention and may .be of the character disclosed and claimed in my Patent 2,112,054, grantedMarch 22, 1938, for. Operating mechanisms. The solenoid plunger I is connected to the rod 2 .by achain linkage. 3. that .is normally guided on .aroller dcarried by .a crank.5. .When the crank 5-is held=in the position shownby means of a pivoted latch.6, .energization .of the solenoid and downward movement .of. the. plunger I cause closing. .movement .ofthe rod 2 against the bias of the spring 2. In the closed position shown the solenoid p-limger .is suitably held in such position by .prop .means ,1. -.When the breaker is to be tripped in the usual. manner, the standard potential .coilais energized causing clockwise rotation of. the. latch. .arm. 9 so as to release the crank roller 1.0. .Underbias of; the spring 2 crank 5 rotates clockwise and the resulting slack in the chain ii-permits the breaker to open. In view of the fact thatthe latchfi engages directly the. crank.5,.it willbe apparent that can 8 cannot utilizecomparatively.feeble impulses to move thelatch 6 against the reacting force even if this force. is greatly. reduced at the crank 5.

For the purpose of efficiently operating the above-described mechanism when but feeble tripping impulses are available, there is providedan auxiliary tripping unit, generally indicatedat ll, including a supporting. member or plate l2 that can be suitably .boltedas at [3 to the main .mechinism plate 14. Suitably mounted on the support are a sensitive .trip coil; 15 having a plunger. 16 for coactingwitha pivoted latch 11, and a crank or disk 18 ,pivotally supported at 19. having an extending portion includingarollerZO adapted to be engaged by the latch H. .A spring 2| mounted on the sup-port by means .of a fixed guide. 22 pivoted-for oscillation at, is seated between said guide and a collar lt carried. by the spring guide rod 25 that is in turn connected to the crankat 26.

In the position shown the spring 2-! is held under tension by the latch 11 so that upon release of the-latch the spring rotates the crank rapidly clockwise to a limiting position indicated at 21.

For the purpose of transmitting the spring energy to the latch 6 and also for restressingthe spring 2| and resetting the latch IT in accordance with an opening operation of the mechanism, the crank I8 is connected at 28 to a rod or link 29 suitably guided so as to have a lost motion connection at 38 with the latch arm 9. When the spring 2| is released the rapid upward movement of the rod 29 causes actuation of the latch 6 by impact as the rod portion at 30 engages the overhanging lugs 3i by the latch arm.

In view of the fact that a considerable amount of spring energy can be released even by a sensitive latch, it Will be apparent that the added impact eiiect at the latch 6 is very beneficial for obtaining high speed release thereof. In order further to increase the sensitivity of the latch ll, a lost motion connection can also be provided between the trip coil plunger 16 and the latch ll, such as at 32. The degree of st motion can be suitably adjusted at 33.

Assuming now a normal tripping operation is desired, energization of coil I5 causes retraction of plunger I6 and release of latch I! so that the spring 2| is free to elevate the rod 29 and trip the latch 6. The mechanism now moves under the bias of spring 2 to the Open position, and in so doing causes immediate reversal of the rod 29 so as to restress the spring 2| and relatch the crank at in the event that the trip coil I5 is not immediately reenergized. To this end the rod 2 is connected to a crank 34 as at 35 so that as the mechanism opens the crank 34 is rotated counter-clockwise and engages by means of a crank extension 34', a resilient member 35 carried by the rod 29. The opening shock is taken up at 36 coincident with resetting of the tripping mechanism.

It will, therefore, be apparent that the tripping unit H is generally applicable to mechanisms of the above type without in any sense altering the mechanism structure and without mechanism above described. The thrust transb mitting type of mechanism shown by Fig. 2 forms per se no part of the present invention and is disclosed and claimed in my Patent 1,827,626, granted October 13, 1931, for Switch operating mechanism. As in the previous case, an operating solenoid l is used for causing a closing movement of the circuit breaker rod 2. The thrust transmitting structure comprises a crank 40 that is connected at one part to the rod 2 and at another part at M to a collapsible linkage 42. The linkage is arranged to be restrained in the thrust transmitting position shown by a pivoted prop 43, and by the main latch 6 acting on a roller 44 carried at the knee joint of the collapsible linkage.

In the open position of the mechanism the roller 45 engages the solenoid plunger I so that when the latch 6 is in latched position elevation of the plunger l causes rotation of the linkage about the roller 44 in a direction to close the mechanism. In the closed position shown, energization of the potential coil 8 to trip the latch 6 causes release of the roller 44, collapse of the linkage and consequent opening of the mechanism.

The tripping unit H is essentially the same as that previously described and its manner of gengeral application to mechanisms of widely varying types is clearly illustrated. In this case the disk I8 is connected by a link 46 to the latch 5 so as to deliver a hammer blow at 41 when the unit is tripped. For the purpose of resetting the unit in the manner above described, a second link 48 is connected to an extension 49 of the breaker operating crank 40 so that the opening movement effects reverse rotation of the disk in the manner above described. The rod 48 is guided for sliding movement at 50 on the extension 49 and is provided with a buffer spring 5!.

The disk 18 is preferably provided as at 52 with means spaced around the periphery thereof so that the various links above described can be readily connected to corresponding parts of the mechanism in question from practically any angle. The extent of application of the tripping device II to practically any type mechanism where more sensitive tripping is desirable, is readily apparent. As in the previous case the support l2 for the tripping unit can be readily attached in the most suitabl manner to the main mechanism framework with a negligible amount of adjustment.

It should be understood that our invention is not limited to specific details of construction and arrangement thereof herein illustrated, and that changes and modifications may occur to one skilled in the art without departing from the spirit of our invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. The combination with an operating mechanism including latching means for holding said mechanism in closed position, of tripping means for actuating said latching means to cause opening of said mechanism comprising a trip coil sensitive to comparatively small tripping impulses, a latch related to said trip coil, a crank having a portion adapted to be engaged by said latch, a spring connected to said crank arranged so that rotation of said crank is effective to stress said spring, means selectively connecting said crank to said latching means including an adjustable connection whereby a releasing blow is delivered to said latching means under influence of the spring energy in response to actuation of said trip coil, and means including said adjustable connection operatively connecting said crank to said mechanism for causing re-stressing of said spring in accordance with the mechanism opening movement.

2. The combination with an operating mechanism including a latch for holding said mechanism in closed position, of tripping means for actuating said latch to cause opening of said mechanism comprising a trip coil sensitive to a small tripping impulse, a second latch related to said coil, a crank having a portion adapted to be engaged by said second latch, a spring operatively connected to said crank and arranged to be stressed thereby, said second latch arranged to hold said spring in stressed condition, a member connected to said crank having a lost motion connection with said first latch for releasing the same under influence of the spring energy, said member also being related to said mechanism so as to rotate said crank for re-stressing said spring and re-setting said second latch in accordance with the mechanism opening movement.

3. The combination with an operating mechanism of the type requiring a tripping impulse equivalent approximately to 500 watts including a latch for holding said mechanism in closed position, of a detachable and independent tripping unit for actuating said latch to cause opening of said mechanism comprising a support arranged to be mounted with respect to said mechanism, a trip coil sensitive to a tripping impulse of the order of magnitude of approximately 20 voltamperes, a second latch related to said coil, a disk rotatably mounted on said support and having a portion adapted to be engaged by said second latch, a spring connected to said disk so as to be stressed in the latched position of said disk,

a link connected to another portion of said disk for engaging by impact said first latch under influence of the spring energy for releasing said mechanism, said disk having means spaced about the P p ry thereof for selective connection between said disk and said first latch, and means interconnecting said mechanism and disk for restressing said spring and resetting said second latch in accordance with the mechanism opening 10 movement.

CARL THUMIM. RALPH J. BASKERVILLE. 

